Plasma Cleans Accelerators Like Steam Scrubs a Pan express
Inside large particle accelerators, there are hollow metal chambers where beams are accelerated. Over time, grime settles on their walls, like in an old pan. This grime prevents the accelerator from running at full power.
To restore the accelerator's strength, plasma, a glowing gas of argon or neon with a bit of oxygen, is sent into the chamber. In a few hours, the plasma burns off the grime, and the chamber is clean again. But until now, no one knew exactly how hot the plasma is or how quickly it removes the dirt.
In the new work, the plasma was measured with a small probe, and the cleaning rate was measured with a quartz microbalance coated with a film resembling grime. It turned out that the plasma does clean well, but conditions could be tuned even better.
Now engineers know how to tune the plasma so accelerators last longer and need less maintenance.
In the experiment, the quartz microbalance detected mass changes of billionths of a gram: that's like noticing a single speck of dust falling off a hair.